1. Field of the Invention
The present invention relates to a shock-absorbing structure of a battery cover designed to protect battery electrodes and so on in a battery connecting plate (which serially connects together batteries of a vehicle such as an electric car etc.) at the time of a vehicle collision.
The present application is based on Japanese Patent Application No. 2000-155232, which is incorporated herein by reference.
2. Description of the Related Art
In a power source for a vehicle such as an electric car, a hybrid car (powered by electricity and gasoline), etc., a plurality of batteries are serially connected together to provide a battery block (battery assembly), and then opposite ends of this battery block are covered with covers or the like, and this power source device is mounted within a vehicle body.
FIG. 12 shows one form of a battery connecting plate for connecting a plurality of batteries together.
The battery connecting plates 70 and 71 are attached to opposite ends of a battery block 72, respectively, and each of these battery connecting plates has a plurality of Juxtaposed bus bars 75 (made of electrically-conductive metal) mounted on an elongate casing (plate body) 74 made of a synthetic resin.
Each of the bus bars 75 has two insertion holes 78 for respectively passing externally-threaded-type positive and negative electrodes 76 and 77 of the corresponding adjacent batteries 73 therethrough, and these bus bars 75 are fixedly secured to the casing 74 by press-fitting, insert-molding or other ways. Each of the electrodes 76 and 77 is connected and fastened to the bus bar 75 by a nut 79.
Bus bars 83, each having one insertion hole 82, are fixedly secured respectively to opposite ends of the front battery connecting plate 70. The positive electrode 76 of the battery 73, disposed at one end portion of the battery block 72, and the negative electrode 77 of the battery 73, disposed at the other end of the battery block 72, are connected respectively to power wires (not shown), each having a terminal, through the respective bus bars 83.
A cover 80 is pivotably mounted on the casing 74, and when the cover 80 is closed, the bus bars 75 and 83, the electrodes 76 and 77 and the nuts 79 within receiving portions 81 are protected by this cover.
In the above structure, the cover 80 is formed integrally with the casing 74 through hinges. However, as shown in FIG. 13, there is also the case where there are provided a cover 61 and a casing 62 which are separate from each other, and are made of a synthetic resin. In either case, the cover 61, 80 is fixed to the casing 62, 74 by retaining members etc.
In FIG. 13, reference numeral 10 denotes an externally-threaded-type electrode of a battery (not shown), and reference numeral 11 denotes a nut for connecting the electrode 10 to a bus bar or the like.
In the above structure, however, when a large external force b was applied to the cover 61, for example, at the time of a vehicle collision, the cover 61 was broken, and besides an impact was transmitted to the electrodes 10 and bus bars within the casing 62, so that for example as shown in FIG. 14 the distal ends of the electrodes 10 broke through the cover 61 to project to the exterior. This resulted in possibilities that the batteries were short-circuited, which was dangerous, and that the batteries were adversely affected.
In the case of increasing the strength of the cover 61 by increasing the wall thickness of this cover in order to deal with the above problems, the weight of the cover 61 increased, and the resin moldability thereof was affected, and the cost increased. And besides, there was a chance that abnormal sounds were produced because of the increased inertia force of the cover 61 due to vibrations of the vehicle. Furthermore, a large cost was needed for developing a special material of shock-relieving properties, which resulted in a problem that the cost of the cover 61 itself increased.